Boolean Data Type (Visual Basic)
Updated: July 20, 2015
For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.
Holds values that can be only
False. The keywords
False correspond to the two states of
Use the Boolean Data Type (Visual Basic) to contain two-state values such as true/false, yes/no, or on/off.
The default value of
Boolean values are not stored as numbers, and the stored values are not intended to be equivalent to numbers. You should never write code that relies on equivalent numeric values for
False. Whenever possible, you should restrict usage of
Boolean variables to the logical values for which they are designed.
When Visual Basic converts numeric data type values to
Boolean, 0 becomes
False and all other values become
True. When Visual Basic converts
Boolean values to numeric types,
False becomes 0 and
True becomes -1.
When you convert between
Boolean values and numeric data types, keep in mind that the .NET Framework conversion methods do not always produce the same results as the Visual Basic conversion keywords. This is because the Visual Basic conversion retains behavior compatible with previous versions. For more information, see "Boolean Type Does Not Convert to Numeric Type Accurately" in Troubleshooting Data Types.
Booleanis not a numeric type and cannot represent a negative value. In any case, you should not use
Booleanto hold numeric values.
Booleanhas no literal type character or identifier type character.
Framework Type. The corresponding type in the .NET Framework is the System.Boolean structure.
In the following example,
runningVB is a
Boolean variable, which stores a simple yes/no setting.
Dim runningVB As Boolean ' Check to see if program is running on Visual Basic engine. If scriptEngine = "VB" Then runningVB = True End If